1. Technical Field of the Invention
This application discloses embodiments describing apparatuses, systems, and processes by which waste material is treated with H—H—O gas torches and gaseous end product(s) is/are generated that may be used in other commercial or industrial applications.
2. Background of the Invention
Processing of waste material, and especially hazardous waste material, is a continuing problem in many industrial and non-industrial settings. Landfill space is decreasing and costs are rising. Moreover, the shipment and processing of hazardous waste material can pose a significant risk to public health and the environment. In view of these concerns, both the public and private sectors have long sought waste processing solutions that reduce overall waste volume, detoxify hazardous content and/or neutralize or stabilize the waste end products to prevent undesired spreading through leaching, airborne discharge or the like.
Even more desirable would be a system and method which is additionally capable of recovering recyclable materials from the waste and/or producing useable end products. Such a system and method would further reduce the environmental and actual cost of waste processing. Numerous methods have been proposed for the conversion of waste material into energy; the most common of which is incineration
Incineration of waste material has proven useful to reduce overall waste volume, but is a poor solution for hazardous and/or medical waste. One major problem encountered in using incinerators to combust medical waste is the heterogeneity of the waste material, which prevents the incinerators from maintaining a sufficiently high constant temperature to completely treat all of the organic and inorganic material in the waste. For example, a first bag of medical waste may be filled with containers of fluids, while a second bag may contain mostly plastics, paper, rubber gloves, and the like. These two bags, fed independently into an incinerator, would create totally different combustion conditions. The first bag would quench and cool the combustion process, while the second bag would accelerate and raise temperatures. During the low temperature cycle, products of incomplete combustion (pollutants) and potentially hazardous organic materials, such as dioxin, furan, and greenhouse gases, may be generated and ultimately released into the atmosphere. During the high temperature cycle, particulate, nitrogen oxide, and metal oxide emissions increase, including hexavalent chromium, a known carcinogen.
Further compounding the problem, the incineration process introduces the waste material to a high temperature chamber which reacts the waste with large amounts of air, resulting in the production of large amounts of hot off-gas which is laden with entrained particulates and acid gas components.
While the incineration process has been used to recover energy from this hot dirty gas, this method is subject to two main problems. First, heat recovery boilers are susceptible to corrosion from the acid gas and fouling from the particulates, especially above temperatures of 700° C. Second, the slow cooling of gas in a recovery boiler is the major cause for the de novo synthesis of dioxins that occurs in the temperature range of 250-400° C. Thus, energy cannot be safely recovered at temperatures below 400° C. because of the risk of forming dioxins. In a typical incinerator, gases exit the main incineration chamber at 1100° C. and exit the chimney at 150° C. Energy can only be practically and safely recovered in the range from 700 to 400° C., meaning that only about one third of the available energy can be recovered.
Other reactors have not provided an effective solution to the problem either. Joule effect reactors are problematic for processing waste materials that may contain metallic materials. Joule effect heaters employ a pair of electrodes that extend into the reactor bed to electrically heat the reactor bed as well as the waste material contained in the reactor bed. Any molten metallic materials in the waste can provide a conductance path between the electrodes and short-circuit the electrical resistance that generates the joule effect heat. Induction heaters are problematic for other types of waste. In particular, induction heaters are suitable mostly for melting metal and their efficiency and effectiveness are greatly reduced when the waste contains other materials such as cellulose and plastic.
Plasma torches offer an alternative source of heating, and are capable of achieving the high temperatures required to combust a wide range of waste material, independent of the waste composition. The plasma will melt inorganic components of the waste material into an inert slag and will dissociate them from the organic components of the waste, which will form a gas. Plasma torches may still utilize oxygen, however, resulting in the production of large amounts of oxidized matter which may be laden with entrained particulates (soot).
Thus, there is a need in the industry for a system and method of treating waste material or other usable energy containing material in an environmentally friendly manner which may also be capable of recovering recyclable materials from the waste and/or producing gaseous fuel end products.